New classes:
- database_model: Manage the database tables (keys, req, cert, crl, templ)
extracted from widgets/MW_database.cpp
- arguments: parse commandline, dynamically create help text
This is a large squash of many small commits.
Allow porting data from the legacy format to SQL.
Store Binaries base64 encoded and use db->transaction
Update password hash to be 8000 x SHA512 with 8 byte Salt
Add revocations table and fixup CRL generation
Add comment and insertion date columns
Fix column saving, remove trust, add XcaDialog
Allow changing the internal name and comment in Cert/Req details view
Extend Comment functionality, Replace About.ui by XcaDialog.ui
